The invention is directed to an elastomeric bush bearing with improved torsion characteristic. It relates to a bearing of conventional design, with an inner sleeve formed as a hollow cylinder, a sleeve-like outer element concentrically or eccentrically surrounding the inner sleeve, and an interposed elastomeric bearing support which encloses an inner or insertion component.
Bush bearings of this type are frequently used particularly in the automobile industry. They are used to support the components of the wheel suspension and/or the transverse control arms. The bearings dampen the radially and axially introduced forces, such as forces produced by an uneven road surface, to keep noise and vibrations away from the passenger compartment. However, the bearings are not only subjected to radial and axial forces, but also to torsion. Conventional bearings have an inner sleeve encased with an injection-molded polyurethane (PUR) coating; alternatively, the elastomeric bearing support, preferably made of rubber, is fixedly connected with the inner sleeve through vulcanization. This causes a high torque in the bearing support under torsion, which severely stresses the bearing and can prematurely wear the bearing out. Disadvantageously, injection-molding PUR around the inner sleeve also requires contouring of the outer surface of the inner sleeve, typically with longitudinal and/or transverse grooves, to ensure that the PUR adheres to the inner sleeve. A plastic cap must also be pressed onto the end(s) of the bearing during installation to seal the bearing against external contamination.
Disadvantageously, this design must also have a certain play to prevent the inner element from jamming, which can also increase the torsional stress. A bearing of the aforedescribed type is disclosed, for example, in DE 44 291 02 A1.
Unlike the bearing described in the aforementioned German patent application, many of the conventional solutions also include an inner sleeve with a flange disposed on its axial end for sealing the bearing. An inner sleeve with this design, however, is more complex and expensive to manufacture. Moreover, a protective surface layer may have to be applied to the inner sleeve, to protect, in particular, the end face of the flange.
It is therefore an object of the invention to provide an elastomeric bush bearing which is greatly unaffected by torsional stress, which has a simple design and can be manufactured cost-effectively.